1. Field of the Invention
The present invention relates to a wireless chip for chip-to-chip wireless transfer, and more particularly, to a wireless chip for chip-to-chip wireless transfer that can wirelessly transmit and receive data and power.
2. Description of the Related Art
Recently, a study of 3D semiconductor technology for stacking a plurality of chips to reduce the area of an integrated circuit in the process of designing has been conducted. According to a TSV (Through Silicon Via) technology, which is a typical one, communication between chips is made by a via and a bump, unlike the existing MCP (Multi-Chip Package).
However, according to TSV technology, since the via is formed by forming a physical hole in a chip and filling the hole with a metallic material, there is a problem in that the research/development and commercialization costs increase due to the additional semiconductor process. Further, it takes much effort to increase the yield ratio of the via due to a problem like cracks. The TSV technology results in an increase in manufacturing cost.
In order to solve those problems, recently, a technology of chip-to-chip wireless communication has been intensively studied. FIG. 1 is a diagram illustrating the concept of a chip-to-chip wireless communication technology according to the related art. The chips stacked each have an antenna for wireless data transfer between them. In FIG. 1, the antennas of the chips are inductors that induce inductive coupling.
Communication between the stacked chips is made by inductive coupling generated by induct-typed pads. However, such chip-to-chip wireless communication has a problem in that it is difficult and troublesome to supply power to the stacked chips. Accordingly, a method of capable of wirelessly supplying not only data, but power has been studied in recent years.
In order to achieve wireless transmission/reception of data and power, basically, there is a need for an antenna for wireless transfer of power and an antenna for wireless transfer of data for the chip on each layer.
FIG. 2 illustrates an example of a 3D semiconductor having a stacked structure for wirelessly supplying power. For the convenience of description, it is assumed that the pads at the left of the chips are power antennas and the pads at the right are data antennas. The function of wireless transmission/reception of data using an antenna is generally known in the art, so wireless transfer of power is described hereafter.
For wireless transfer of power between chips, in a plurality of stacked chips, the power antenna of the highest chip has only to have a function of transmitting power, the power antenna of the lowest chip has only to have a function of receiving power, and the antennas of the other chips between them has both functions of transmitting and receiving power. Obviously, the functions of the highest chip and the lowest chip may be changed. The principle of wireless power supply is as follows.
First, the highest chip receives DC power through a wire from the outside, converts it into AC power, and transmits the AC power to the antenna of the chip under itself through its power antenna. The chip receiving the AC power wirelessly transmits the power to the chip under itself through its antenna, such that the power is wirelessly supplied to the lowest chip in this way. The chips convert the AC power received through their antenna back into DC power and use it as power for activating themselves.
However, since one chip has two antennas for transferring data and power, the integrated circuit becomes large and complicated, so the manufacturing cost increases.
The background of the present invention has been disclosed in Korean Patent No. 1392888 (May 8, 2014).